JPS5914934A - Manufacture of rubber products reinforced by steel wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION For many commercial rubber products, such as conveyor belts or high pressure hoses, reinforcing inserts of steel with a high carbon content, often in the form of steel wire, are used. It is provided.

A strong and lasting bond between metal and rubber is necessary to ensure good effectiveness and product life.

=3- This is easily obtained only if the filament 1 of the steel wire is plated with a thin layer of α-brass or with other alloys having copper and zinc as main components or with pure zinc.

The wires treated in this way are generally vulcanized directly in a rubber mixture, which in particular contains adhesion-promoting additives.

Adhesion between brass-plated steel wire and rubber is generally caused by sulfur being present as a vulcanizing agent in the rubber to be vulcanized. Under vulcanization conditions this sulfur reacts with the brass or alloy layer to form copper sulfides and/or zinc sulfides, and in this way the steel wire adheres to the cross-linked rubber.

If rubbers that can be cross-linked using peroxides are used, the bonding method described in item 1 will not work because sulfur cannot be used as an adhesive. It is also not possible to add sulfur as a component of the mixture to rubbers that can be crosslinked with peroxides, since undesirable reactions occur between sulfur and peroxides that lead to considerable disruption of the crosslinks in the rubber. be.

In this technology, it is desired to provide a peroxide crosslinkable rubber with reinforcing steel inserts, and good adhesion between the steel and the rubber must be provided. .

This need is met by the teachings according to the invention described below.

The fact that sulfur greatly interferes with the cross-linking process by peroxides leads to the conclusion that both sulfur and peroxides should not be present in the same rubber mixture. It is therefore necessary to use sulfur and peroxides each in two separate mixtures, so that they can react in each case at the vulcanization temperature without adversely affecting each other.

Figure 1 shows rubber reinforced with steel wire.

This rubber contains sheaths (1) and (5) consisting of rubber mixture A cross-linked with peroxides and a sulfur 5-yellow or sulfur carrier and the reaction of sulfur with brass or alloys. It consists of underlayers (2) and (4) of a rubber mixture B which provides adhesion to the brass-plated or other alloyed steel wire (3).

The open bonding of layers A and B occurs due to the migration of peroxide from mixture A into mixture B, whereby a peroxide cross-linking process occurs in both mixtures.

For the reinforced rubber in the drawing to be effective, the following conditions are necessary: a) It is at least partially soluble in the polymer and its decomposition temperature is lower than the temperature at which sulfur reacts with brass. Choose a peroxide (or peroxide-based) that has a high As a result, the cross-linking effect of mixture A only occurs when mixture B and the copper wire are bonded together.

b) Accurate metering of sulfur or sulfur donor, which in excess would interfere with the subsequent cross-linking of mixture B.

C) Accurately metering the peroxide to properly cross-link mixture B.

d) a thin enough layer (
1. Preparing the mixture 13 in film or solution form.

Therefore, the present invention provides a method for preparing steel wires of A3 m+n containing 0.5 to 10 parts by weight of sulfur based on 100 parts by weight of rubber in rubber mixture B or a corresponding amount of sulfur carrier. 1 to 15 parts by weight of rubber based on 100 parts by weight of rubber in rubber mixture A;
Rubber mixture A containing a peroxide having a decomposition point of 130 to 22 (')' C or higher is applied to the rubber compound B; =7- Providing a method for producing reinforced rubber products comprising a brass-plated steel wire or a steel wire provided with an alloy layer, which is characterized in that it is vulcanized, and a rubber product 13 that can be cross-linked with peroxide. It is something to do.

The steel wire used has a standard diameter. Depending on the intended use, it can be used in single strands or in bundles. Brass is a preferred alloy.

Mixture B preferably contains the following polymers: nibutanine rubber, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene-propylene-tene polymer, ethylene-propylene copolymer. , ethylene-vinyl acetate, fluorocarbon polymers, imprene rubber, whether fully or partially hydrogenated or carboxylated, 1. acrylonitrile, butadiene-copolymers, natural rubber, silicone rubber, optionally carboxylated styrene-butadiene rubber, and terpolymers of vinyl acetate, butyl acrylate and acrylonitrile.

Rubbers can be cross-linked with peroxides. Chlorinated polyethylene is a preferred polymer.

The rubbers can also contain common auxiliaries, provided that the auxiliaries do not interfere with the interaction between the sulfur and the surface of the steel wire and do not interfere with the cross-linking of the rubber by peroxides.

The following may be mentioned by way of example: stabilizers such as M
gO; fillers such as carbon black, chalk and/or plasticizers.

The amount of sulfur in rubber mixture B, based on 100 parts by weight of rubber, is preferably from 3 to 6 parts by weight, especially from 4 to 5 parts by weight.

The layer thickness of the rubber mixture B of the steel wire is preferably 0°()1.
~2 mm, especially 0.5~lvn.

Rubber mixture B is applied to the steel wire-1- in a manner known to those skilled in the art. For example, the steel wire can be introduced into a B(7) dipping bath, or a piece of rubber mixture B can be wrapped around the steel wire, or the wire can be extruded and coated in an extruder. .

Rubber mixture A may be composed of the same polymers specified for rubber mixture B.

However, this does not mean that the rubber mixtures A and B9- always contain the same polymers, since the polymers can be completely different. Thus, for example, mixture A and mixture B can in each case consist of chlorinated polyethylene as polymer. However, mixture B can also consist, for example, of chlorinated polyethylene and of mixture AIJ'EPDM rubber.

Chlorinated polyethylene is the preferred rubber for Rubber Mix A.

Rubber mixture A can also contain auxiliaries which do not interfere with the peroxide crosslinking process. Bifillers such as carbon black or chalk; stabilizers such as MgO or lead oxide; and/or plasticizers.

Examples of peroxides used in rubber mixture A include: 1,1-bis(tert-butyloxy)-3,3,5-)limethylcyclohexane,
Perbenzoic acid [-butyl, 3,3-bis-(E-10-phthylberoxy)7tanecarboxylic acid-butyl ester, tsucumyl peroxide and 1,3-bis-(i-butylperoxyisopropyl) -Benzene.

Activators such as triallyl cyanurate-1 or triallyl isocyanurate can also be added to the peroxides or peroxide mixtures in a conventional manner.

The amount of peroxide in the rubber compound A is preferably from 3 to 10 parts by weight, especially from 5 to 8 parts by weight, per 10 parts by weight of rubber.

Rubber mixture A is applied to rubber mixture B in a customary manner, for example by envelope or extrusion coating.

Vulcanization is carried out under pressure using common vulcanization methods, such as steam, hot air or compression in common machines.

The applied vulcanization temperature is preferably 150-190°C.

The products obtained according to the process of the invention can be used, for example, as conveyor belts, e.g. as hoses for medium, high or maximum pressures, as ■-belts, with teeth [11 bells) and
- It can be used as a driving bell 1 or as a buffer bell.

Experiments show that the adhesion values obtained using sulfur are e.g. l')
This represents a much higher standard than that required for the manufacture of high-pressure hoses according to T N 2 On 22.

They also show that the adhesion after heat aging and dynamic strain is better than the real tear resistance of rubber (
After the adhesion test, the surface of the wire was coated with rubber).

The preferred arc profile should contribute to the "stabilizing" effect of sulfur, which counteracts the negative effects of zinc on the aging resistance of chlorinated polyethylene mixtures by chemical combination with brass. Ras.

Lit mixture used to produce test objects
Details of A and B are shown in Table I. Magnesium oxide was used as a stabilizer in mixture B (instead of the basic lead silicate used in mixture Δ), so that the desired reaction between sulfur and brass resulting in adhesion was not interfered with.

The sample mixture A was rolled into a film on a forming drum with a total sheet thickness of 3m+n. Brass-plated steel wire (7
x3
, W perchlorethylene or toluene mixture: light oil 1:1; mixture of 1 part by weight of melt axillary: 5 parts by weight of solvent). rolled.

After evaporation of the solvent, three siliconized paper strips were coated with 8% and then with mixture A in the axial direction of the drum (
total thickness 3mm).

After bandaging the forming drum with a moist cotton wire, vulcanization was carried out in steam (30 minutes/160° C.).

13- Test objects with the following dimensions were cut from vulcanized cylinders: 15 (1 n + n x 25 mm (tested for separation resistance after static storage) - 1300 + n x 25 mm (dynamic) Separation resistance was tested after target fatigue).

In order to provide as much information as possible regarding the practical suitability of the rubber-metal bond obtained, the adhesion forces in the test objects were tested before and after heat aging and after heat aging and subsequent dynamic fatigue. .

Separation resistance (according to peel test) was tested according to DTN 53530. Aged and unaged test objects were used for testing (24 hours and 168 hours/150
℃).

Dynamic fatigue test is ASTM D-43O-59 (73),
It was carried out according to Method A (Scotto 7 Rexing Machine). Following this method, an attempt was made to simulate the stresses in reinforced hoses in a pulsation test in order to obtain information on the suitability of rubber-to-metal bonds in practical applications.

For this purpose, test objects (30
0x25mm) was used. The test specimen I + turnip was sandwiched between both ends in the test apparatus, and as a result, the intermediate portion (stressed sample length 13 (l mm)) was mechanically loaded.Identification of the mechanically loaded portion This allows the existing separation resistance to be clearly separated from other load parts.

-Mackerel-' 11-Adhesive strength before and after aging (Table 2): 90 N/
The separation resistance measured at c port 1 is l:) T N 2
+1 was much higher than the minimum value required for high pressure hoses according to 22 (Hippo”, 40 N/CM + core: 2
5N/cm).

After aging (7d/150°C), the rubber-metal adhesion is 4
The separation resistance of 6 N/cm remained higher than the tear propagation resistance of rubber.

The separation resistance results after heat aging were comparable to those in Table 2.

The fracture profile after dynamic fatigue shows that the steel wire surface is 1,47+),
It shows that the premature aging caused by the zinc in the brass was not observed in the rubber layer which was still coated with rubber after 10 bends and was directly adjacent to the brass.

Ll-: Adhesion of chlorinated polyethylene to brass-plated steel wire GoL-11 = to B□Chlorinated polyethylene (Bayer CM3630) 100.0
Magnesium oxide 100 -1
0.0 Basic lead silicate 10.0
-Anti-aging agent (Vulkanox HS l
0120.2 Carbon Black N 762
60°o ao.

Plasticizer (ReoIIlol LTM)
20.0 20.0 Trialkyl cyanurate (TA
C) 4.0 4.0 ester (Trigo
nox 17/40) 7.0 - Sulfur
-□■ 2Q1.2 198.2 Mixer batch temperature 125℃ 1
25℃Table 1 (continued b) F (MPa), 160℃ 30' 16
．． 9 5.8 [) (%), 160℃ 3
0' 395 990S IOO(MPa)
,] 60'C30' 3.2 +, 5
S 300 (MPg>, 160℃ 30'+4.2
3.31st issue A) +60'c 30'
67 65R (%), 160°C30”
29 27-] 3 Physical properties, standard frame II F (MPa), 160°C 30' +8.4 7
．． 9D (%), 160℃ 31)' 375
890S 100 (MPa), 160'C30'3.4
+, BS 300 (MPa), 160℃30'
+5.2 3.8 Density (+r/cm')
1. aa 1,350' carbon black O'
Carbon black N-762N-762 Lead silicate＼' u l kanox HS Magnesium oxide V u 1kanox T-1s Plasticizer Bayer CM3630 Plasticizer, TAC1
17- Bayer CM 3630 11/2' TAC, 1172' Empty Trigonox17/40 2' Empty 11th! L9 temperature 125℃ Beating at 125℃: Roller 60℃ Preparation mixing: Roller 60℃ O' finished mixture 0' batch 172' treatment 1/2' sulfur 3' treatment completed 2' treatment 4' treatment completed -λ Static adhesive strength (N/20mm> and residual adhesive strength after heat aging (%) 0 value 225+) (100%)2
After 4 hours/150°C 135+) (60%) After 168 hours/150°C 1] 5+) (51%) 10) Table of structural damage in rubber - Adhesive strength (N/25mm) and belt bending fatigue + ) Residual adhesive strength (%) = 18- -941, -□-After cooking -111--2202
15 (98%) nJ11] After rubbing (4+J245,00
0s) a-ri) 235 230 (98%) 72
After opening/at room temperature (approximately 735,000 strokes) O value (
Approximately 72...Time after dynamic fatigue 140°C
) +30 120 (92%) p Rike Tomo μ (Basic (approximately 245.000 strokes) +32 120491
%] 72 hours 1 ull/after room temperature (approximately 735,000 strokes) ++) ASTM r) -4,30-59 (73
) Belt bending fatigue test object according to: Number of bends until layer separation Test condition 1 Force K
(N) 3330-ra-φd(
30 stroke frequency n (1/min) 170 (1 stroke = 2 bends) Compressed sample length 1E/(width) 130 Sample width 1) (mm) 2
5 samples: Thickness l'+ (mm) (Total of steel wire inserts) Sample: Length l (mm)
300 Description F = Strength according to DrN53504 (MPa) r) = DI
Elongation at break according to N53504 (%) S = DrN53
Tensile according to 504 (MPa) H = Hardness according to DIN 53505 (Shore A) R = Impact elasticity according to DIN 53512 (%)

[Brief explanation of the drawing]

Figure 1 shows rubber reinforced with steel wire. Patent applicant: Bayer Akchengesellschaft

Claims (1)

[Claims] 1. Steel wire containing 0.5 to 10 parts by weight of sulfur or a corresponding amount of sulfur carrier based on 100 parts by weight of rubber in rubber mixture B. covered with a rubber mixture B having a layer thickness of 3 mm; containing a peroxide having a decomposition point of 130° C. or higher of 1 to 15 parts based on 100 parts by weight of rubber of the width of the rubber mixture A; Apply rubber mixture A to rubber mixture B; and then apply the layers together at 130-220°
1. A method for producing reinforced rubber products comprising alloy-coated steel wire reinforcement and peroxide cross-linkable rubber, comprising vulcanization at temperatures above C. 2. The method according to claim 1, wherein the alloy is brass. 3. The method according to claim 1 or 2, wherein the amount of sulfur is 3 to 6 parts by weight. 4. The method according to claim 1 or 2, wherein the amount of sulfur is 4 to 5 parts by weight. 5. The layer thickness of rubber mixture B of 2. Steel wire is 0.01 to 2 m.
The method according to any one of claims 1 to 4, wherein m. 6. The layer thickness of the rubber mixture B in the second steel wire is (), 5 to 1 m.
The method according to any one of claims 1 to 4, wherein m. ? 8. The method according to any of claims #1 to 6, wherein the amount of peroxide in rubber mixture A is 3 to 1 (> parts by weight). 8. The amount of peroxide in rubber mixture A A method according to any one of claims 1 to 6, wherein the amount is from 5 to 8 parts by weight. 9. A method according to any of claims 1 to 6, wherein the rubber of rubber mixture B is chlorinated polyethylene. The method according to any of Item 8. 10. The rubber of both Nocom mixture is chlorinated-2
= Polyethylene. The method according to any one of claims 1 to 8. 11. The method according to any one of claims 1 to 10, wherein the vulcanization temperature is 150 to 190'C. ]2. A method of making reinforced rubber articles substantially as described with reference to any of the Examples. 13. A rubber product containing reinforcing material manufactured by the method according to any one of claims 1 to 12.